He was with his mom, twin sister, and nanny who were taking pictures of the hotel when he he wandered away. According to Mercury News: "Police said the family was not lodging there, simply stopping in for shelter from the soggy day and to absorb the festive atmosphere when they realized he was missing."
If you recall, authorities found the boy, who was not breathing and had to be revived using CPR, near a Christmas tree at the end of a two-foot-deep trough that drains the fountain.
Hyatt has put up a temporary barrier until they figure out how to permanently remove the fountain.
Our thoughts go out to the family. Sad.